Period/ovalation after coil

So I got my coil out in March and I had a normal period ect a few weeks after I then had normal symtoms for my period and ovaluation. But I am now 13days missed period and I did a test last week at 6days late, but it was negitive I‘m getting discharge again but the app keeps pushing my period and ovalation forward how do I know when I’m predicted to ovulate/ next period. I know my discharge is a good idea when I am ovulating but I would like to know when my next period is due/expected.